IDEA-52806 JAVA: smarter parameter name completion for Builder-style-methods

java/java-impl/src/com/intellij/codeInsight/completion/JavaMemberNameCompletionContributor.java

@@ -110,6 +110,9 @@ public class JavaMemberNameCompletionContributor extends CompletionContributor {
     if (variableKind == VariableKind.PARAMETER) {
       final PsiMethod method = PsiTreeUtil.getParentOfType(var, PsiMethod.class);
       propertyName = PropertyUtil.getPropertyName(method);
+      if (method != null && method.getName().startsWith("with")) {
+        propertyName = StringUtil.decapitalize(method.getName().substring(4));
+      }
     }
 
     final PsiType type = var.getType();

java/java-impl/src/com/intellij/psi/impl/source/codeStyle/JavaCodeStyleManagerImpl.java

@@ -52,6 +52,7 @@ public class JavaCodeStyleManagerImpl extends JavaCodeStyleManager {
   @NonNls private static final String IS_PREFIX = "is";
   @NonNls private static final String FIND_PREFIX = "find";
   @NonNls private static final String CREATE_PREFIX = "create";
+  @NonNls private static final String WITH_PREFIX = "with";
   @NonNls private static final String SET_PREFIX = "set";
 
   private final Project myProject;

java/java-tests/testData/codeInsight/completion/variables/locals/WithBuilderParameter.java

@@ -0,0 +1,4 @@
+public class Builder {
+  public Builder withSomething(String so<caret>) {}
+}
+

java/java-tests/testData/codeInsight/completion/variables/locals/WithBuilderParameter_after.java

@@ -0,0 +1,4 @@
+public class Builder {
+  public Builder withSomething(String something<caret>) {}
+}
+

java/java-tests/testSrc/com/intellij/codeInsight/completion/VariablesCompletionTest.java

@@ -78,6 +78,9 @@ public class VariablesCompletionTest extends CompletionTestCase {
   public void testUniqueNameInFor() throws Exception {
     doTest(getTestName(false) + ".java", getTestName(false) + "_after.java");
   }
+  public void testWithBuilderParameter() throws Exception {
+    doTest(getTestName(false) + ".java", getTestName(false) + "_after.java");
+  }
 
   private void doTest(String before, String after) throws Exception {
     configureByFile(FILE_PREFIX + "locals/" + before);